Papers by Keyword: Telescope

Abstract: We report on an ambitious project in the field of automation, applied to bound and free abrasive processing of precision and ultra-precision surfaces, with potentially far-reaching consequences. This involves two main aspects:- directly processing surfaces using industrial robots, and combining robots with Zeeko CNC polishing machines to automate operations that are currently manual. These form steps towards our ultimate vision of the Integrated Manufacturing Cell for bespoke optics rather than mass-produced, and manufacture of other precision surfaces including prosthetic joint implants. Projects such as the European Extremely Large Telescope provide a relevant case study, where significant numbers of high-value bespoke optics are required.

Abstract: The use of hydrostatic bearing for support of telescope offers a number of potential performance advantages, but the structure parameter of bearing is the main factor which influence the bearing. The temperature rise of bearing is also important for the stiffnees of the telescope mount.In addition to the known benefit of mount stiffness and tracking accuracy from exceedingly low friction, the hydrostatic bearing provides a wide range of geometric possibilities for large telescopes [1].This paper analyzes various familiar hydrostatic bearing for the azimuth and elevation axes of telescope.Theoretical calculation and simulation show that the performance of bearing meets telescope’s design requirements.The principle and process of this work and Finite Element Analysis (FEA) are introduced in detail. According to the CFX result, the structure parameter and performance of bearing ,temperature field and pressure distribution have obtained.

Abstract: The structure of core shaft combined with mercury belt is widely used as the primary mirror supporting structure of 1 meter class and 2 meter class large aperture telescope currently. In order to reduce the structure jitter of primary mirror, the fitting clearance between core shaft and shaft sleeve is very small, so clamping stagnation occurs during installation and disassembling process of core shaft. The removal method of clamping stagnation of core shaft is introduced. Mechanical analysis of core shaft and primary mirror is applied to make sure that the primary mirror is safe. Some tools are designed specially, and the process and the attention points to remove core shaft are introduced. In this way, the clamping stagnation of core shaft can be removed easily. The core shaft of 1 m class primary mirror was removed by the method and the primary mirror was excellent without damage.

Abstract: China is now building the largest single dish radio telescope in the world in Guizhou province, which is called Five-hundred meter Aperture Spherical radio Telescope (FAST). A Stewart platform is introduced in FAST as an accuracy adjustable mechanism for feed receivers. The main purpose of this paper is to discuss dimension optimization design method of the Stewart platform based on three optimization objective functions. The optimization objective functions can reflect the operability and accuracy of the Stewart platform, and optimization design flow is presented according to the important degree of the three optimization objectives. Finally, a set of optimized parameters is obtained, and the study in this paper provides a basis for the coming optimization the feed support system for FAST in the next step.

Abstract: This paper reports the initial development and testing of an innovative technique for measuring rail displacements that combines remote video monitoring with particle image velocimetry (PIV). A webcam combined with a small telescope is used to monitor rail movements. Results from a laboratory trial, in which the movements of a hydraulic actuator were monitored, demonstrate that the system can measure the peak-to-peak displacements of the actuator to within 0.1mm from 15m away. Results from a section of railway track near Crewe are also reported.